1. Field of the Invention
This disclosure relates to a shutter opening/closing mechanism for opening and closing a toner supply port of a toner container as a cover of an image forming apparatus main body is closed and opened, and an image forming apparatus provided with the same.
2. Description of the Related Art
In an image forming apparatus such as a copier or a printer for electrophotographically forming an image on a sheet, an amount of toner corresponding to a consumed amount is supplied from a toner container to a developing device when toner in the developing device is consumed in the case of adopting the developing device using a two-component developer. The toner container is mounted and detached by opening a cover of an image forming apparatus main body and inserting or withdrawing the toner container into or from the image forming apparatus main body. The toner container is provided with a container shutter for opening and closing the toner supply port to prevent the toner from scattering around when the toner container is mounted or detached. The toner supply port is closed by the container shutter when the toner container is mounted and detached. When the toner container is mounted into the image forming apparatus main body, the toner container is moved to open the toner supply port, thereby enabling toner supply.
A shutter opening/closing mechanism for linking opening and closing movements of a toner supply port by a container shutter with closing and opening movements of a cover of an image forming apparatus main body is known in conventional image forming apparatuses. The shutter opening/closing mechanism includes a joint member to be connected to a coupling member of the container shutter, a rotary member (main body joint gear) for holding the joint member, and a spring for biasing the joint member toward the container shutter. In the shutter opening/closing mechanism, the main body joint gear is rotated as the cover is opened and closed, with the result that the joint member rotates. When the joint member rotates, the coupling member rotates to move the container shutter, whereby the toner supply port is opened or closed.
With such a shutter opening/closing mechanism, upon mounting the toner container at a predetermined position in the image forming apparatus main body, the toner container is inserted to the predetermined position with the joint member temporarily retracted toward a side opposite to a biasing direction by the spring. When the toner container is inserted to the predetermined position, the coupling member and the joint member are arranged to face in the biasing direction, wherefore the joint member moves forward in the biasing direction to be connected to the coupling member.
In the conventional shutter opening/closing mechanism as described above, for example, the toner container is inserted to the predetermined position with the joint member held in contact with a chamfer (inclined surface) formed on the coupling member, whereby the joint member is pushed by the inclined surface and temporarily retracted to the side opposite to the biasing direction. However, in the case of a structure in which the joint member is pushed and retracted by the inclined surface of the coupling member as described above, resistance may increase when the toner container is inserted.
Upon pulling out the toner container at the predetermined position, the toner container cannot be pulled out straight since the joint member is connected to the coupling member. Thus, it has been necessary to obliquely pull the toner container out while slightly rotating the toner container about the coupling member.